"There is some prospect of rehabilitation even if the prognosis is poor," Mr Gallowes said.

But Justice Stephen Kaye said he was concerned Hicks carried the baton intending to use it "if necessary".

"You couldn't argue the proposition that this case falls squarely into the most serious cases of murder," Justice Kaye said.

Ms Williams said Hicks had an extensive criminal record, with nine court appearances before his murder trial dating back to 2007 for crimes including wilful damage, thefts and burglaries, and had breached almost all orders made against him.

The last, a community corrections order for a 2011 armed robbery, was made two months before Zayden's murder.